In recent years, an increase in a number of cases, in which LANs (Local Area Network) are constructed in offices, ordinary homes, and the like, has been accompanying drastic pervasion of Internet. A need for constructing a LAN wirelessly, a so-called wireless LAN is remarkably uprising with help from progress in digital wireless communication technique, because wiring is troublesome. Moreover, a large number of pervaded wireless LANs in use is expected in the future because such wireless LANS can be used for a mobile terminal including a laptop under a mobile environment. IEEE 802.11 that has already been standardized by IEEE (Institute of Electrical and Electronics Engineers) is a typical technique of this wireless LAN. This standardized technique defines a physical layer to a MAC (Media Access Control) layer, which is a lower layer of a data link layer, in an OSI (Open Systems Interconnection) model. This standardized technique can replace that of the Ethernet®, which is a wired transmission channel of a LAN. Furthermore, the technique has a specification capable of providing a roaming function as an additional function realized by being wireless.
At present, preparation of a new terrestrial digital broadcast, which will take over a terrestrial analog broadcast watched all over. Japan, is proceeding. This terrestrial digital broadcast started in three big Japanese metropolitan areas, Kanto, Kinki, and Tokai areas in 2003. The terrestrial digital broadcast is planned to be extended all over Japan in 2006. This movement is accompanied by a plan to abolish the present analog broadcast in 2011.
ISDB (Integrated Services Digital Broadcasting) is a concept of next-generation integrated digital broadcasting, which treats all information such as a video image, sound, and data as digital data. Digital television broadcasting, digital sound broadcasting, facsimile broadcasting, and multi-media broadcasting are studied as a specific service of the ISDB. Utilization of a satellite broadcast wave, a terrestrial broadcast wave and wired transmission channels such as a coaxial cable and an optical fiber is examined as a transmission channel for the ISDB.
The technical standard ISDB-T (Terrestrial) of this terrestrial digital broadcast employs OFDM (Orthogonal Frequency Division Multiplexing) using many carrier waves (carrier) in a modulation system. Accordingly, ghost disturbance caused by plural propagation channels (multi pass) such as reflection caused by a building can be prevented. Moreover, the ISDB-T has plural specifications for each of a transmission mode defining intervals of carriers, a modulation system of each carrier, and a guard interval provided for every effective symbol period in a time-axis direction. In the standard, a considerable number of signal formats are admitted. In practice, the most appropriate format is selected among these specifications, according to services such as fixed receiving and mobile receiving.
Moreover, in the ISDB-T, one transmission channel (communication channel) (frequency band of substantially 5.6 MHz) is divided into 13 segments (1 segment=substantially 430 kHz). Modulation systems are changed per segment. This allows a broadcast station to arbitrarily decide a signal structure so as to carry out, for example, (i) sound broadcast and high definition broadcast, or (ii) standard fixed broadcast and mobile broadcast, by one transmission channel.
Furthermore, the ISDB-T adopts an interleave in a time-axis direction and an electric wave utilized is appropriate for transmission to a moving object. Accordingly, one distinct feature of the ISDB-T is that the ISDB-T allows consistent receiving even by a mobile terminal, for example, a mobile receiver such as an in-vehicle TV, a PDA (Personal Digital Assistants), a cellular phone, and the like. A service supposing such mobile receiving is greatly expected in the future.
In a wireless AV (Audio-Visual) system constructed upon the technique mentioned above, means for causing devices in the system to recognize each other, which devices perform wireless communication, is necessary.
For example, as illustrated in FIG. 8, the wireless AV system is constructed by (i) wireless centers (transmitters) 122a through 122c and (ii) a receiver which wirelessly receives a content stream from one of wireless centers (transmitters) 122a through 122c and reproduces the content stream. In such a wireless AV system, a receiver side needs to identify a wireless center out of the wireless centers (transmitters) 122a through 122c with which a communication pair with the receiver is established. Various methods are proposed for a method for establishing a communication pair between wireless communication devices and a method for identifying the communication pair.
For example, Patent Document 1 cited below discloses a system in a digital cordless telephone device. In the system, (i) a main phone or a handset is allowed to wirelessly transmit to another main phone or another handset a code for calling up a system provided mutually in the main phone and the handset and (ii) the another main phone and the another handset stores in a memory this received code. This system makes it possible to easily set plural main phones and handsets to be operable in the same wireless systems.
Moreover, Patent Document 2 cited below discloses a device control system. The system includes a device being subjected to a control and a controller for controlling the device via a transmission channel. The device includes (i) device state management means for managing a state of a main body of the device, and (ii) setback notification means for notifying information concerning the state of the main body of the device in a case where the state of the main body of the device changes. The controller includes state information receiving means for receiving information concerning the state from the device. This allows the controller, in a case where the state of the device changes, to promptly comprehend the state of the device after a change in the state in the device control system constructed by a device being subjected to the control and the controller for controlling the device.    (Patent Document 1)    Japanese Unexamined Patent Publication 46662/1995. (Tokukaihei 7-46662) (published on Feb. 14, 1995)    (Patent Document 2)    Japanese Unexamined Patent Publication 215483/2002 (published on Aug. 2, 2002)
However, the wireless AV system as illustrated in FIG. 8 is used in order to wirelessly connect plural AV devices in a general household. Accordingly, plural AV devices are provided relatively close to each other. As a result, in this case, interference may occur in such an exchange of control data as mentioned above.
For example, in FIG. 8, a user tries to receive a stream from a wireless center 122a by a receiver 133 and carry out an operation so as to reproduce the stream. In this case, a connection processing, in which the wireless center 122a transmits an ID of the wireless center 122a to the receiver 133 and the receiver 133 identifies this ID, is performed. Then, a wireless communication pair between these devices is established.
However, at the same time as the connection processing mentioned above, a similar connection processing may be performed at the wireless center 122b closely positioned. In this case, the receiver 133 may mistakenly receive an ID of the wireless center 122b, which ID is transmitted from the wireless center 122b to another receiver. To explain more specifically, in a case where the receiver 133 receivers and identifies the ID from the wireless center 122b ahead of the ID from the wireless center 122a, the receiver 133 establishes a connection to the wireless center 122b but does not connect to the wireless center 122a. 
In this case, the receiver 133 reproduces a stream from the wireless center 122b with which the receiver has mistakenly established a communication pair. However, the user is not notified that the wrong communication pair is established because the operation of the receiver 133 is normal.
The present invention is attained in view of such a case. Accordingly, the purpose of the present invention is to provide a wireless terminal, a base device, a wireless system, a wireless terminal control method, a base device control method, a wireless terminal control program, a base device control program, and a computer-readable storage medium, which can notify a user an establishment of a wrong connection in a case where a wrong wireless connection for the user is established.